Method for producing a woven fabric

ABSTRACT

The invention relates to a method for producing a woven fabric by means of a device, wherein in one weaving step respectively one shed is formed by means of warp threads, through which shed a weft thread is introduced and the weft thread is pushed in the direction of a woven fabric edge by means of a weaving reed. An angle for entering a weft thread is variably adjusted by means of a weft thread entering device. According to the invention, the angle of the weft thread to be entered in relation to the warp threads is adjusted between 40° and 90° by means of an adjustment unit, wherein the weft thread entering device is positioned by means of an electric drive via a gear with respect to the predetermined angle.

The invention relates to a method for producing a woven fabric, wherein in each weaving step a weaving shed into which a weft thread is inserted is formed by means of warp threads and the weft thread is displaced in the direction of a woven-fabric periphery by means of a weaving reed.

Weaving machines for producing woven fabrics and such woven fabrics are known from the prior art. At least two thread systems intersect in a perpendicular manner during weaving, wherein the one thread system is the warp system and the other thread system is the weft system. Pre-tensioned warp threads form a carrier sheet into which weft threads are successively drawn in from one woven-fabric selvedge to the other across an entire weaving width which is formed by means of the warp threads. For example carpets, wall coverings, woven composite fabrics, woven rubber backings, and other industrial textiles are producible by means of weaving. Weaving machines are typically used for making woven fabrics on an industrial scale. The warp threads here are guided from a rear side of the weaving machine toward the front, wherein the weft threads are in each case conveyed from one side to the other between the warp threads forming the so-called weaving shed. In the completed woven fabric, the warp threads are held together by means of the weft threads.

U.S. Pat. No. 1,280,461 A1 describes a device for producing a woven fabric having warp threads forming a weaving shed and weft threads which are inserted into the weaving shed by means of a weft-insertion device. Furthermore, a weaving reed for beating the weft threads in the direction of a woven-fabric periphery are provided. The weft-insertion device is configured in such a manner that an angle for inserting the weft thread and for beating the same is adjustable within a range of approximately 45°. To this end, a screw connection which is guided in slots is provided.

The invention is based on the object of stating a method for producing a woven fabric which in relation to the prior art is improved, and such a woven fabric.

The object in terms of the method is achieved by the features stated in claim 1, and in terms of the woven fabric by the features stated in claim 9.

Advantageous design embodiments of the invention are the subject matter of the dependent claims.

A method for producing a woven fabric provides that in each weaving step a weaving shed through which a weft thread is inserted is formed by means of warp threads, and the weft thread is displaced in the direction of a woven-fabric periphery by means of a weaving reed. Here, by means of a weft-insertion device an angle for insertion of the weft thread is adjusted. According to the invention the angle of the weft thread to be introduced in relation to the warp threads by means of a readjustment unit is adjusted between 40° and 90°, wherein the weft-insertion device in relation to the predetermined angle is positioned by means of an electric drive by way of a gear unit.

On account thereof, that the angle for weft insertion is variable adjusted, the weft threads are interwoven into the woven fabric according to that angle. It is possible in this way for the weft threads rather than the warp threads to form a supporting structure of the woven fabric.

On account thereof, that an angle of the weft thread to be introduced in relation to the warp threads is adjusted between 40° and 90° by means of a readjustment unit, it may be substantially ensured that the angle is precisely adjusted during an entire production process and that the weft threads in relation to the warp threads run at one and the same angle.

In order for the desired angle for weft insertion to be adjusted, the weft-insertion device is in particular positioned by means of a turntable, on which the weft-insertion device may be disposed, and by means of a sprocket. Moreover, a scale by means of which the respectively adjusted angle is displayed may be provided.

For example, the method makes it possible for a woven fabric having weft threads which within the woven fabric run obliquely to the warp threads to be produced such that process steps, in particular in the rubber-processing industry, such as the perpendicular disposal of the two types of threads in the prior art, are no longer required. For example, the process steps involving diagonal cutting of blanks and the subsequent joining of the tailored woven-fabric layers prior to vulcanizing may be dispensed with.

Since joining of tailored woven-fabric layers is not required in the case of a woven fabric produced in this manner, there is also no joint seam which may form unevenness and/or an abutment joint in the woven fabric.

In one advantageous embodiment of the method an angle for beating the weft thread against the woven-fabric periphery in relation to the warp thread is likewise variably adjusted. The weft thread is thus not only introduced into the weaving shed so as to correspond to the adjusted angle, but is also beaten up against the woven-fabric periphery of the woven fabric at this angle, on account of which the woven fabric is configured in a particularly homogeneous manner.

Particularly preferably, the readjustment unit is automatically displaced in the direction of the warp threads so as to depend on a length of the woven fabric, so that no deployment of personnel is required for positioning the readjustment unit. Moreover, on account of automatic positioning the readjustment unit is always in an optimal position in relation to the weaving shed in order for the next warp thread to be inserted.

A beating movement of the weaving reed against the woven-fabric periphery is generated by means of at least one cylinder-and-piston unit of the readjustment unit, so that the respective weft thread is precisely beaten up against the woven-fabric periphery so as to be independent of the adjustment of the angle, on account of which the woven fabric is homogeneously configured.

In one potential embodiment, the at least one cylinder-and-piston unit is pneumatically activated, on account of which a piston for generating the beating movement is moved by means of compressed air from a cylinder of the cylinder-and-piston unit. On account of the cylinder-and-piston unit being activated by means of compressed air, advantageously no hydraulic fluid and thus no hydraulic pump and/or a pressure reservoir are required, such that the pneumatic solution is a comparatively cost-effective alternative.

Particularly preferably, the weft-insertion device is displaced in the direction of the warp threads so as to depend on a length of the woven fabric, on account of which the respective weft thread is inserted into the weaving shed in an optimal manner. The weft-insertion device in the case of this embodiment is preferably linked to the readjustment unit, such that both the weft-insertion device as well as the readjustment unit may be displaced and positioned in an optimal manner so as to depend on the length of the woven fabric.

In one particularly advantageous embodiment of the method the weft-insertion device and/or the readjustment unit are/is actuated by means of a control unit. On account thereof, production of the woven fabric may be performed in a largely fully automatic manner so that a comparatively minor deployment of personnel is required.

Furthermore, automatic positioning of the readjustment unit in relation to the woven-fabric periphery is performed by means of signals detected by a detection unit. The detection unit is preferably connected to the control unit so that positioning of the readjustment unit may be automatically performed by means of signals detected by the detection unit.

The invention moreover relates to a woven fabric which is produced by means of the above-described method. The weft threads here are introduced into the woven fabric in such a manner that the weft threads in relation to the warp threads run at an angle between 40° and 90°.

In such a fabric the warp threads rather than the weft threads, as is known in the prior art, form a supporting structure of the woven fabric.

Exemplary embodiments of the invention will be explained in more detail in the following by means of drawings, in which:

FIG. 1 schematically shows a readjustment unit of a device for carrying out a method for producing a woven fabric; and

FIG. 2 schematically shows a plan view of the device for producing the woven fabric.

Identical and equivalent parts are provided with the same reference signs in all figures.

FIG. 1 shows a readjustment unit 1 of a device 2 for producing a woven fabric 3 having obliquely running weft threads 3.1, which is illustrated in more detail in FIG. 2.

Weaving machines for producing woven fabrics 3 which are formed by warp threads 3.2 and weft threads 3.1 are known from the prior art.

The warp threads 3.2 are tensioned and fixed on the weaving machine, wherein in each weaving step by means of the warp threads 3.2 a weaving shed into which a weft thread 3.1 is introduced and is guided from one woven-fabric selvedge to the woven-fabric selvedge lying opposite thereof is formed. In such a woven fabric 3 the weft threads 3.1 run perpendicularly to the warp threads 3.2, forming a supporting structure of the woven fabric 3.

In the rubber-processing industry, woven fabrics 3 specified in this manner are cut to blanks in a diagonal manner at a predetermined angle, and the woven-fabric layers which have been cut to form parallelograms are subsequently joined together, in particular by means of adhesive bonding. On account thereof, undesirable abutment joints and/or unevenness may be created, whereby tires and inner tubes, for example, are produced by means of such joined-up woven-fabric layers.

In order for a number of process steps, in particular diagonal cutting and joining, in the rubber-processing industry, for example, to be able to be reduced, it is provided that the weft threads 3.1 are introduced into the weaving shed at a predetermined angle in relation to the warp threads 3.2 between 40° and 90°. It is moreover provided that the weft thread 3.1 which in each case has been introduced at the predetermined angle by means of a weaving reed 5 is also beaten up against the woven-fabric periphery of the woven fabric 3 at this angle.

To this end, the device 2 for producing a woven fabric 3 has a weft-insertion device 4 which is illustrated in more detail in FIG. 2 and which is connected to the readjustment unit 1.

The readjustment unit 1 is disposed above the warp threads 3.2 and has two cylinder-and-piston units 6, wherein in each case one cylinder-and-piston unit 6 is linked to one end 5.1 of the weaving reed 5. In particular, an exposed end of a piston 6.1 is linked to the weaving reed 5, wherein the cylinders 6.2 are fastened to a retaining element (not shown in more detail). For example, a threaded rod for adjusting the relative position of the two cylinder-and-piston units 6 to one another is disposed between the retaining element and the respective cylinder-and-piston unit 6. The pistons 6.1 of the cylinder-and-piston units 6 are moved in relation to the cylinder 6.2 when the threaded rod is rotated, on account of which the weaving reed 5 is also moved. The cylinder-and-piston units 6 here are pneumatically activated, that is to say by means of compressed air.

Alternatively, the cylinder-and-piston unit 6 may also be activatable hydraulically, by motor drive and/or in any other suitable manner.

An angle of the weaving reed 5 in relation to the warp threads 3.2 is adjustable by means of the retaining element to which the two cylinder-and-piston units 6 are fastened, so that the weft thread 3.1 which is in each case inserted into the weaving shed by means of the weaving reed 5 is beaten up against the woven-fabric periphery according to that angle. As described above, an angle between 40° and 90° is adjustable so that the weft threads 3.1 are interweavable into the woven fabric 3 in an obliquely running manner. The weaving reed 5 by means of the readjustment unit 1 is moved in such a manner that the respective weft thread 3.1 is positively beaten up against the woven-fabric periphery so as to be independent of the adjusted angle.

The pistons 6.1 are extendable from the cylinder 6.2 and retractable thereinto, on account of which the weaving reed 5 performs a reciprocal movement and, in order for the woven fabric 3 to be formed, beats the weft thread 3.1 which has been introduced in the respective weaving step up against the woven-fabric periphery. The reciprocal movement of the weaving reed 5 is performed in the direction of the progression of the warp threads 3.2, so that the warp threads 3.2 are guided in a linear manner.

A displacement path of the pistons 6.1 for beating up the warp threads 3.1 is between 7 cm and 10 cm, for example, so that the respective piston 6.1 is extendable from the cylinder 6.2 by between 7 cm and 10 cm. The two cylinder-and-piston units 6 are actuated by way of signals from a detection unit (not shown here), in particular a proximity switch which may be disposed on a secondary shaft of the device 2.

The retaining element to which the cylinders 6.2 of the cylinder-and-piston unit 6 are fastened is displaceably disposed on the device 2, so that the readjustment unit 1 is positionable so as to correspond to the length of the woven fabric 3. The readjustment unit 1 here is connected to a control unit (not shown) and is actuated by means of the latter, so that positioning of the readjustment unit 1 is automatically performed.

In one preferred embodiment the weaving reed 5 is connected to a so-called weaving sley which is a component part of the weft-insertion device 4, as is illustrated in FIG. 2. The weft-insertion device 4 in particular is configured as a so-called gripper device.

The gripper device has a feeding gripper element 4.1 and a receiving gripper element 4.2. The weft thread 3.1 for insertion into the weaving shed is fixed to the feeding gripper element 4.1 and is guided by means of the feeding gripper element 4.1 to the center of the weaving shed. There, the weft thread 3.1 is transferred to the receiving gripper element 4.2, by means of which the weft thread 3.1 is guidable to the woven-fabric selvedge.

The weaving sley and the weaving reed 5 are configured so as to be unipartite and to be positionable in relation to the warp threads 3.2 at a predetermined angle between 40° and 90° by means of the readjustment unit 1. On account thereof, the weft thread 3.1 is inserted into the weaving shed and beaten up against the woven-fabric periphery by means of the weaving reed 5 at this angle.

The weft-insertion device 4 in relation to the predetermined angle is positionable by means of an electric drive by way of a gear unit, wherein to this end the weft-insertion device 4 and the readjustment unit 1 may be disposed on a turntable which is linked to a sprocket in order for the corresponding angle to be adjusted. Preferably a scale by means of which the respective and momentarily adjusted angle is displayable is provided.

The embodiment of the device 2 for producing the woven fabric 3, which is shown in FIG. 2, has a warp-thread system 7, the weft-insertion device 4 on which a warp-thread lifting device 8 is disposed, a fabric take-off 9, a fabric stand 10, and a winding device 11 for winding up the finished woven fabric 3, wherein the cylinder-and-piston units 6 and the weaving reed 5 are not illustrated.

The warp threads 3.2 by means of the warp-thread system 7 of the device 2 are capable of being provided in a tensioned manner for the weaving operation, wherein the warp threads 3.2 extend across a predetermined portion of the device 2.

The weft-insertion device 4 is actuated by means of the control unit and automatically positionable depending on the length of the woven fabric 3.

As described above, the weft-insertion device 4 has the warp-thread lifting device 8 by means of which a predetermined number of warp threads 3.2 are liftable in order for the weaving shed for the insertion of a weft thread 3.1 to be formed. The weaving shed here, as does the weft-insertion device 4, extends obliquely to the warp threads 3.2

Moreover, the weft-insertion device 4 is linked to the readjustment unit 1 (not shown), wherein the readjustment unit 1 is disposed so as to be parallel with the weft-insertion device 4.

The produced finished woven fabric 3 is removed from the device 2 by means of the fabric take-off 9, and by way of the fabric stand 10 is guidable to the winding device 11 in order for the woven fabric 3 to be wound up. The warp-thread system 7 and the fabric take-off 9 are fixedly positioned and communicate with one another, so as to enable the woven fabric 3 to be woven at a predetermined weft-thread density and warp-thread tension.

The winding device 11 may be embodied as a batching motion winde or as a center winder, for example, wherein the winding device 10 is disposed so as to be parallel with the fabric take-off 9.

In order for the angle at which the weft threads 3.1 in relation to the warp threads 3.2 are introduced into the weaving shed and are beaten up against the woven-fabric periphery to be adjusted, the weft-insertion device 4, together with the warp-thread lifting device 8 and the readjustment unit 1, is adjustable in relation to the warp threads 3.2 between 40° and 90°.

Adjustment of the angle is preferably performed automatically by means of the control unit.

LIST OF REFERENCE SIGNS

1 Readjustment unit

2 Device

3 Woven fabric 3.1 Weft thread 3.2 Warp thread 4 Weft-insertion device 4.1 Feeding gripper element 4.2 Receiving gripper element 5 Weaving reed 6 Cylinder-and-piston unit

6.1 Piston 6.2 Cylinder

7 Warp-thread system 8 Warp-thread lifting device 9 Fabric take-off 10 Fabric stand 11 Winding device 

1. A method for producing a woven fabric by means of device, wherein in each weaving step a weaving shed through which a weft thread is inserted is formed by means of warp threads, and the weft thread is displaced in the direction of a woven-fabric periphery by means of a weaving reed, wherein by means of a weft-insertion device an angle for insertion of the weft thread is variably adjusted, wherein the angle for insertion of the weft thread in relation to the warp threads by means of a readjustment unit is adjusted between 40° and 90°, wherein the weft-insertion device in relation to the predetermined angle is positioned by means of an electric drive by way of a gear unit.
 2. The method as claimed in claim 1, wherein an angle for beating the weft thread against the woven-fabric periphery in relation to the warp thread is variably adjusted.
 3. The method as claimed in claim 1, wherein the readjustment unit is automatically displaced in the direction of the warp threads so as to depend on a length of the woven fabric.
 4. The method as claimed in claim 1, wherein a beating movement of the weaving reed against the woven-fabric periphery is generated by means of at least one cylinder-and-piston unit of the readjustment unit.
 5. The method as claimed in claim 4, wherein the cylinder-and-piston unit is pneumatically activated.
 6. The method as claimed in claim 1, wherein the weft-insertion device is displaced in the direction of the warp threads so as to depend on a length of the woven fabric.
 7. The method as claimed in claim 1, wherein the weft-insertion device and/or the readjustment unit are/is actuated by means of a control unit.
 8. The method as claimed in claim 1, wherein automatic positioning of the readjustment unit in relation to the woven-fabric periphery is performed by means of signals detected by a detection unit.
 9. A woven fabric which is produced by means of a method as claimed in claim 1, wherein the weft threads in relation to the warp threads run at an angle between 40° and 90°. 